Electric fuse



Feb. 6, 1923. 1,444,637

N. W NUTT ELECTRIC FUSE Original Filed Jan. 29,

Fig 1 Fig 5 20 mitnpamaz ilnumxur W 5 Wm H MEL Patented F ch, 6, 1923.

UNITED STATES NORMAN W. NUTT. O TR'ENTON, NEW JERSEY.

ELECTRIC FUSE.

Application filed January 29, 1919, Serial No. 273,710.

To all whom it may concern:

Be it known that I, NORMAN VJ. Nu'r'r, a citizen of the United States, "t irling at Trenton, in the county of Mercer and State of New Jersey, have invented. a new useful Improvement in Electric Fuses, which the following is a specification.

My invention has for its objects the production of a safe and etficientelectric .iiuse at a moderate ost ol manufacture, and the provision of means therein for preventing; the rupture of the device by the gases gen-- erated within it upon the burning-out of the fuse therein by excessive current, and the visible external indication of the destruction of the fuse when such destruction occurs.

In the accompanying drawings, forming}; a part of this specification, Fig. l is a side elevation of the insulating member of the casing of the device as the same appears when completely "formed for assemi. U with the other elements of the structure; Fig. 2 shows said insulatingmember in plan view .ietore it is completely termed tor such assemblage; Fig, 3 is a vertical central sect-ional View, on an enlarged scale, Y 0 rice when assembled without a li ,ing oi refractory material; Fig. 4 is a similar view on a like scale, disclosing the structure pro rided with a filling of granular refractory material; Fig. 5 is a plan view, on enlarged. scale, of the contact-end of the device; Fig. 6 is an interior view of the device Wltii the cap removed.

In constructing my device, 1 provide a threaded metal terminal, 1, within which is placed the insulating member, 2. This insulating member is made, preferably, of vulcanized fibre and is cut or stamped out of a blank in the form shown in Fig. 9. of the drawings, a circular opening, 3, being formed in one of the radiate portions for the passage therethrough of the t e. and an oblong opening, 4, for securing an end-terminal, being formed in the centre e'l. the insulating member. This stamped fib e is then bentinto the form shown in FE and 6, :tleXures of the body being etle t at the places marked. by dotted lines in r 2. so that the radiate portions term a dung, d. circular wall which, when subjected to internal pressure, will expand slightly and present slight interstices between the panels formed by the radiate portions A thin an- Renewed December 13, 1922.

sulatii A member. 2. A. fibre disc, 10, haring diametrically opposed peripheral notches, ll, 12, and a central aperture corresponding in size and form with the central opening. 4, in the insulating member, 2, is positioned to overlie the closed end oi": said member, 2, with its central aperture registeringwith the aperture, 4, and to embrace within its peripheral notches, 11 and 12, respectively, the upturned projections, 13 and 14. oi the flange, 8, oi the threaded terminal, i. A. thin meal disc. 15, having a central opcnh 1' .cspond and register with the aperture, 4, in the insulating member, 2, and. the ceu 1 opening in the fibre dis, it"), is pla "(1 upon the inner iace of the end wall, 9, or the insulating member, and the meta terminal, .=..(3, provided with is adjusted to said fibre disc.

ears. i7 and I 1.0, so as to cover the central opening therein, and. said ears are passed through the three said central apertures in the end-wall, 9, fibre disc, 10, and metal disc, 15, and are bent or clinched over the inner face of the disc. 15, to clamp said elements firmly together, as shown in Figs. 3 and 6 of the drawings. The fuse, 19, is then soldered at its ends to the threaded terminal, 1, and the end-terminal, 16, and the structure is closed by 5: 1e metal annulus, 20, embracing the mica disc, 21, said annulus being turned clamped upon the flann embrace and firmly hold to :1 the m V the insulat- I produce a fuse device n 3 .rijers-titial easing which withstands t entire crof the fuse are enabled to es ape from the fuse chamber through the interstices betv. en the panels and through the thread of the terininal, 1, and any slight crevices between the other assembled parts of the device; but all flame is confined entirely within the fuse chamber, while a portion of the products of combustion of the fuse is deposited upon the inner face of the mica disc, 21, and accords visual evidence of the burning-out of the fuse.

By uniting the threaded terminal, l, with the end terminal, 16, with intervening in sulating members, in the manner described, I prevent. all relative IROVETDGIYLS of the two terminals and consequent weakening or rupture of the fuse or separation thereof from either terminal.

If desired, the fuse chamber may be filled with granular refractory material obtai ed, preferably. from broken pottery or a burnt clay product of similar character, such filling tending to absorb the force of an explosion of gases within the fuse chamher and to smother or absorb the flame produced thereby.

Having thus d scribed my invention, it claim 1. An electric fuse comprising a retair ig member and an e3"- ansible lining positioned. and expansible within said retaining memher.

2. An electric fuse comprising a retaining member and an enpansible lining therefor, the respective parts of which are capable o. fill electric fuse coin rising a retaining;

present member having an insulating expansible lining, a terminal carried thereby, an insu lsting dish locked to the terminal and a screw terminal locked to the disk.

6. An electric comprising;' a retaining member having an insulating expansible lining, a terminal carried ther by. an insulating disk locked to the terminal and a screw terminal locked to the dish, said disk having notches. therein and said. screw terminal havinn; lugs engaged in said notches. v

T. In an electric fuse, an insulating expansible lining having a perforated bottom. a sectional side wall and sectional flanges integral with the sections of the side wall.

Mlell sscs.

FRANK l. Cassy, ALEXANDER Tenn 

